MX2007005384A

MX2007005384A - Exchange needle retractable safety syringe.

Info

Publication number: MX2007005384A
Application number: MX2007005384A
Authority: MX
Inventors: Graeme Francis Walton; Alan Walsh
Original assignee: Global Medisafe Holdings Pty L
Priority date: 2004-11-04
Filing date: 2005-04-04
Publication date: 2007-09-27
Also published as: EP1830910A4; IL183014A0; US20090118677A1; JP2008518693A; WO2006047810A1; ZA200704624B; RU2007119986A; CU23262A3; CN101094704A; JP4791480B2; CA2586705A1; RU2363500C2; BRPI0516705A; KR20070097428A; AP2007004025A0; EP1830910A1

Abstract

A safety syringe comprising a syringe barrel (12), a plunger (13), a needle (14), a needle hub (15) integral with the needle, a needle gland (16) to accommodate the needle and hub, and a needle cap (19) to protect the needle prior to use. The plunger has engagement means (25, 36) located on its end to engage with the needle hub in order to retract the needle from the gland and into the syringe barrel after the syringe has been used. The plunger is provided with a threaded split bush (28), which has a multi start thread. When the plunger is fully retracted with the needle attached, the plunger has one or more lugs (31) that come into contact with the threaded split bush so that the plunger is thereby locked. Hence the needle is locked in the barrel. The plunger may be snapped off retaining the needle safely within the syringe barrel.

Description

RETRACTABLE RETRACTING NEEDLE SAFETY SYRINGE Technical Field This invention relates to a safety syringe having a retractable needle for use in the medical or dental profession or in the personal administration of drugs in such a way that the physician, surgeon or other operator of the needle can be protected from damage by the needle after use. In particular, it relates to safety syringes where there is a requirement to accommodate various sizes of needles or where a needle change is required between filling the syringe from a bottle and supplying an injection to the patient. BACKGROUND OF THE INVENTION The danger of damage and possible infection by the HIV virus or Hepatitis B is well documented for medical practitioners who use needles in the normal course of their profession. In addition, people who have the habit of taking drugs themselves run a severe risk of contacting any of the specified viruses or actually contacting other viruses if a needle, once used, is re-used in a unsterilized form. There are also additional hazards when it is required to replace the needle in the syringe. There have been many proposals aimed at reducing - the number of so-called needlestick injuries and several attempts have been made to provide a safe system for the removal of such needles once used, but such previous proposals have had deficiencies. OBJECT OF THE INVENTION It is an object of the present invention to provide a syringe having a retractable surgical needle, which is capable of accommodating various sizes of surgical needles or which allows the needle to be changed between filling the syringe from a vial and supplying of the injection to the patient. It is also an object of the invention to provide a syringe employing such a retractable needle in a sterile manner prior to use and to permanently store the surgical needle, once used, in a substantially secure manner. Finally, the invention provides an alternative means for providing an exchange needle and / or accommodating the needle of a syringe used to protect against accidental damage arising from unwanted contact with the exposed needle once the syringe has been used. Although the following description generally refers to a syringe of conventional size, no such limitation is intended thereby and reference to a syringe means that it encompasses any other combination of syringes. needle / syringe including filiform syringes, wherein, by suitable adaptation, the invention can also be usefully applied. DESCRIPTION OF THE INVENTION The invention provides in a broad manner a safety syringe incorporating a retractable exchange needle having a syringe barrel which has a plunger slidably located therein, with piston means located toward the end of the remote plunger from the end of the barrel from which the plunger extends, the barrel of the syringe also having means for removably attaching a needle installation to the end of the barrel opposite to that from which the plunger extends, the needle installation comprising , a needle, an integral needle core with the needle, a needle cap to accommodate the needle and core, and a needle cover to protect the needle before use; wherein the plunger has clutch means located at its end to engage with the core of the needle in order to retract the needle from the socket and into the barrel of the syringe after the syringe has been used and where the plunger is provided. with a threaded slit collar, characterized in that the inside of the threaded slit collar has a m-start thread that when the plunger is completely retracted with the needle attached, the plunger has one or more stops that - they come into contact with the threaded slit collar which thereby secures the plunger and therefore the needle in the barrel in such a way that the plunger can be suddenly released by retaining the needle securely within the barrel of the syringe. Preferably the bushing is adjusted to the end of the barrel by the threaded means. Before use, the needle cover protects the needle from damage and also acts as a safety cap for medical personnel who use the syringe to avoid needlestick injuries. The presence of the needle cover also means that the needle installation can be conveniently changed without the risk of a needle puncture injury that could occur if the needle were unprotected. The needle sleeve is preferably held in the needle cover by the interference fit. Preferably there are matching grooves on the outside of the needle cap that coincide with the grooves on the inside of the needle cover. The core of the needle is pushed towards the needle cap and held in place by a matching ring that is of an interference fit. By this method a sealing fit is achieved. After installation, i.e. after the needle cap is assembled with the inside of the needle and the protective needle cover is adjusted, the installation is screwed into the end of the barrel. A sealing point is secured by means of matching tapers between the needle cap and the interior of the threaded barrel. The barrel of the syringe is preferably made of transparent plastic and is graduated to read the fluid level. After the needle hub with the needle core is screwed into it, it is screwed into the barrel and the seal is achieved, the needle cover of the installation is removed leaving the needle ready for use. In this way, various sizes of needle installations can be adjusted to the barrel. The piston is preferably made of synthetic rubber and is fitted to the plunger in order to seal by means of an interference fit between the plunger and the barrel, thereby allowing the fluid to be extruded from the syringe, through the needle, in the common way. Preferably, the plunger has at its end a fastener for engaging with the core of the needle after the plunger has ejected the fluid from the syringe, i.e. after completing an injection. When the two coinciding parts are pressed together, the plunger is then drawn back causing the core of the used needle including the steel needle to come out of the needle cap. Then the needle is connected to the end of the plunger and can be withdrawn into the body of the syringe. Preferably the plunger has a rapid release point created by the reduced diameter near the piston. When the plunger is released suddenly, the syringe becomes inoperative. The threaded slit collar is located around the plunger body and pressed towards the end of the barrel and held in place by means of an interference fit and a matching notch. Preferably, within the slit collar there is a multi-start thread which when the plunger is fully retracted with the needle attached, the plunger has one or more stops which contact the threaded slit collar. When the threaded slot collar is thus engaged by the plunger, the plunger is secured at the end of the barrel. The plunger can then be released suddenly. The rapid release point on the plunger is preferably designed to break clean and flat with the upper part of the barrel making it difficult to remove the needle from the barrel. Optionally the method of securing the core of the needle to the plunger can be inverse, i.e. The female half can be found at the end of the needle core and the male locking protrusion is located on the plunger. Also the protrusion on the end of the plunger (male adjustment) can incorporate a stainless steel fastener that has an edge that is secured in the core of the needle when it is fully engaged after the injection of a medical fluid. In this mode, the pressed stainless steel fastener is made of sheet and is pushed over the male protrusion. The stainless steel fastener is made in the shape of a "C" section that is clamped around the male protrusion approximately 5mm in length with an edge forming on one side to interact with the inner wall of the needle core to the termination of the injection. After the patient's needle is withdrawn, the plunger is pulled back, the stainless steel ridge in the plunger that is secured in the needle core causes the needle core and thus the needle to retract towards the body of the barrel causing the needle to be stored safely against human damage. The separation of the needle from the plunger can not be achieved and when the plunger is retracted and secured in the threaded slit collar and the plunger is released suddenly, the syringe is secured and is unable to be used again. It should be noted that the protrusion in the plunger has an interference fit for the interior of the needle core and this becomes obvious when the syringe is filled prior to injection at which point the plunger "reaches the bottom" in the barrel of the syringe. syringe. However, after the injection one more stroke is required strong to overcome the initial resistance in order to really secure the needle core on the plunger. The advantages of the invention are found in: 1. The manual retraction of the needle preferably uses a stainless fastener. 2. The twist lock slit collar secures the plunger in the barrel before releasing the plunger. 3. Using the above principles, the plunger can be retracted without splashing fluid caused by self-retracting syringes. 4. The thread in the needle installation allows varying the gauge of the needle and / or the exchange of the needle can be made after the syringe has been filled from a bottle before injection. BRIEF DESCRIPTION OF THE DRAWINGS. The invention can be better understood from the following non-limiting description of a preferred embodiment, in which: Figure 1 is a cross-sectional view of a syringe installed in accordance with an aspect of the invention in which the end of the plunger has a female part, Figure 2 is an exploded cross-sectional view of the components used in the installation of syringe of Figure 1, Figure 3 is a cross-sectional view of a syringe according to a second embodiment of the invention, wherein the plunger has a male part, Figure 4 is a detailed side view of a plunger and a needle for use in a syringe according to the second embodiment of Figure 3, Figure 5 shows the detail of the stainless steel fastener used in the plunger of Figures 3 and 4, and Figure 6 is a perspective view of a Slit collar for use with the syringe of any modality. DETAILED DESCRIPTION OF THE INVENTION Referring generally to Figures 1 and 2 there is shown a syringe and needle combination generally referred to in 11, which comprises a barrel of syringe 12, a plunger 13 and a needle 14. Needle 14 is provided with a needle core 15 at its upper end. The needle core 15 is pressed towards the needle cap 16 and held in place by a flange 17 around the periphery of the core 15 which engages a corresponding cavity 18 around the inner periphery of the cap 16 in an interference fit . In this way a sealant adjustment is achieved - by this method A needle cover 19 protects the needle from damage and also acts as a safety cap for medical personnel who use the syringe avoiding needlestick injuries. The needle cap 16 is held in the needle cover 19 by an interference fit. There are matching striations 20 on the outside of the needle cap 16 that coincide with the complementary cavities 21 inside the needle cover 19. After it is assembled into the needle cap 16 with the needle 14 and the cap is adjusted 19, the installation 14, 16, 19 is screwed into the end 22 of the barrel 12. A sealing point is achieved by means of the matching tapers between the needle cap 16 and the inside of the threaded portion 22 of the barrel 12. The barrel 12 is transparent plastic and graduated to read the fluid level. After the needle installation 14, 16, 19 is screwed into the barrel 12 by virtue of the bushing 16 which is screwed therein and the seal is achieved, the needle cover 19 is removed leaving the needle 14 seen for use . Various sizes of needle installations 14, 16, 19 can thus be adjusted to the barrel 12. The plunger 13 is provided with a piston 23 of synthetic rubber that fits the plunger 13 and is sealed by means of an interference fit between the plunger 13 and the barrel 12 allowing the fluid to be extruded from the syringe 11 in the common manner. The piston 13 has at its end 24 a fastening means 25 which in this mode is a female fastener installation for engaging with a male portion 26 correspondingly designed on the needle core after the plunger 13 has expelled the needle. fluid (not shown) of the syringe 11. When the two matching parts 25, 26 are pressed together, the plunger 13 is attracted back causing the needle core 15 used including the steel needle 14 to exit the needle cap 16. The needle 14 is now connected to the end of the plunger 13 and can be withdrawn towards the body 12 of the syringe 11. The plunger 13 has a rapid release point 27 by means of the reduced diameter near piston 23. When it is suddenly released, the syringe 11 thus becomes inoperative. A threaded slot collar 28 is located around the body of the plunger 13 and is pressed towards the end of the barrel 12 and held in place by means of an interference fit of a flange 29 on the collar and a matching notch 30 in the barrel 12. Within the slit collar 28 is a multi-start thread.

- - When the plunger 13 is fully retracted with the needle 14 attached, the two stops 31 located on the plunger 13 come into contact with the threaded slit collar 28. When the threaded slit collar 28 is thus engaged by the plunger 13, the plunger 13 is thereby secured to the end of the barrel 12. The plunger 13 can now snap off at the rapid release point, which is designed to break clean and flat with the top of the barrel 12 thus making it difficult to remove the needle 14 of barrel 12. Returning to Figures 3, 4 and 5, there is shown a syringe 11 having a plunger 13 of an alternative embodiment in which components similar to those illustrated in Figures 1 and 2 refer to the same numerals . However, in this case, the method for securing the core 15 of the needle to the plunger 13 is opposite in that the female portion 36 is located at the end of the needle core 5, while the male protrusion 36 is located at the end of the plunger 13. In this case, the protrusion 36 at the end of the plunger 13 is fitted with a stainless steel fastener 33 (shown in detail in Figure 5) having an edge 34 that is secured in the core of the plunger. needle 15 when fully engaged after injection of a medical fluid. The pressed stainless steel bra 33 is made of laminate and pressed on the male profusion 32. The stainless steel fastener is made in the form of a "C" section that is clamped around the male profusion 32 of about 5mm in length with the edge 34 forming on one side for interact with the inner wall of the needle core 15 at the end of the injection. The edge 34 can be square shaped as shown or for example in a triangular shape ending at a point for a greater pressure capacity. When the plunger 13 is attracted back, after the needle 14 of the patient has been removed, the stainless steel ridge 34 in the plunger 13 is secured in the needle core 15 and retracts the needle core 15 and thus the needle 14 towards the body 12 of the syringe 11 causing the needle 14 to be stored safely against human damage. The separation of the needle 14 from the plunger 13 can not be achieved and when the plunger 13 is retracted and secured in the threaded slit collar 28 (as in the first Figures 1 and 2) and the plunger 13 the blow is released, then the syringe 11 is secured and is not capable of being used again. Figure 6 shows an alternative threaded slit collar 28 for use in any embodiment of Figures 1 to 2 or Figures 3 to 5, where a quadruple start twist thread 37 is used. It will be appreciated by those skilled in the art that Many modifications and variations may be made to the embodiments described herein without departing from the spirit or scope of the invention. Throughout the specification the word "comprises" and its derivatives are proposed to have an inclusive rather than exclusive meaning unless the context otherwise requires.

Claims

CLAIMS 1. A safety syringe having a syringe barrel incorporating a retractable exchange needle has a plunger slidably located therein, with piston means located toward the end of the plunger away from the end of the barrel from which the barrel extends. plunger, the syringe barrel further having means for removably attaching a needle installation to the end of the barrel opposite that from which the plunger extends, the needle installation comprising a needle, a needle core integral with the needle , a needle cap to accommodate the needle and core and a needle cover to protect the needle before use; wherein the plunger has coupling means located at its end to engage with the core of the needle in order to retract the needle from the cap and into the barrel of the syringe after the syringe has been used and wherein the plunger is provided. with a threaded slit collar, characterized in that the inside of the threaded slit collar has a multi-start thread that when the plunger is fully retracted with the needle engaged, the plunger has one or more stoppers that contact the collar of threaded slit thus securing the plunger and therefore the needle in the barrel, in such a way that the plunger can be released at a stroke by retaining the needle securely inside from the barrel of the syringe.
2. A safety syringe according to claim 1, characterized in that the bushing is fitted to the end of the barrel by threaded means.
3. A safety syringe according to any of claims 1 or 2 characterized in that before use, the needle cover protects the needle from damage and also acts as a safety cap for the medical personnel using the syringe avoiding the needle puncture injuries.
4. A safety syringe according to any of the preceding claims, characterized in that the needle cap is held in the needle cover by an interference fit.
5. A safety syringe according to claim 4, characterized in that there are coincidence grooves on the outside of the needle cap that engage with the grooves on the inside of the needle cover.
6. A safety syringe according to any of the preceding claims, characterized in that the needle core is pressed towards the needle sleeve and held in place by an interference fit.
7. A safety syringe according to the claim 6 characterized in that after the installation of the needle in the needle cap and that the needle protection cap is adjusted, the needle installation is screwed into the end of the barrel.
8. A safety syringe according to claim 7, characterized in that a sealing point is secured by means of matching tapers between the needle cap and the interior of the threaded barrel.
A safety syringe according to any of claims 7 or 8, characterized in that after the needle installation is screwed into the barrel and the seal is achieved, the needle cover is removed from the installation leaving the Needle ready for use.
10. A safety syringe according to claim 9, characterized in that various sizes of needle installations are able to fit the barrel of the syringe.
11. A safety syringe according to any of the preceding claims, characterized in that the barrel of the syringe is preferably made of transparent plastic and is graduated to read the level of the fluid.
12. A safety syringe according to any of the preceding claims characterized in that the piston is made of synthetic rubber and conforms to the plunger in order to seal by means of an interference fit between the plunger and the barrel, thereby allowing the fluid to be extruded from the syringe, through the needle, in the common manner.
A safety syringe according to any of the preceding claims, characterized in that the piston has at its end a fastener for coupling with the core of the needle after the piston has expelled the fluid from the syringe, in such a manner that when the two matching parts are pressed together, the plunger is attracted back then causing the core of the used needle including the steel needle to exit the needle cap and withdraw towards the body of the syringe.
A safety syringe according to any of the preceding claims, characterized in that the piston has a rapid release point created by means of a reduced diameter near the piston, so that when the piston is released suddenly, the syringe It becomes inoperative.
A safety syringe according to any one of the preceding claims, characterized in that the threaded slit collar is located around the plunger body and is pressed towards the end of the barrel and held in place by means of an adjustment of interference
16. A safety syringe according to claim 15 characterized in that the slit collar has a multiple start thread therein, such that when the plunger is completely retracted with the needle engaged, the plunger has one or more stops coming into contact with the threaded slit collar and in this way the threaded slit collar is engaged by the plunger and by this the plunger is secured to the end of the barrel.
17. A safety syringe according to claim 16 characterized in that the plunger is suddenly released to render the syringe inoperative.
18. A safety syringe according to any of the preceding claims characterized in that the method of securing the core of the needle to the plunger is by means of a female portion located in the core of the needle and a male protrusion located at the end of the plunger.
19. A safety syringe according to claim 18 characterized in that the male protrusion in the plunger incorporates a stainless steel fastener having an edge that is secured in the needle core when fully engaged after injection of the fluid doctor.
20. A safety syringe according to the claim 19 characterized in that the stainless steel fastener is made of a pressed sheet and pressed onto the male protrusion, the stainless steel fastener being made in the form of a "C" section that is clamped around the male protrusion and it is provided with an edge formed on one side to interact with the inner wall of the needle core at the end of the injection.